Excess Mortality in Kidney and Kidney-Pancreas Transplant Recipients in the COVID-19 Pandemic in Portugal-A Cohort Study

Risk factors associated with 30-day mortality following COVID-19 infection in patients receiving kidney replacement therapy in Australia and New Zealand

BACKGROUND AND AIMS

The COVID-19 pandemic impacted greatest among patients with pre-existing chronic health conditions, including chronic kidney disease. This retrospective cohort study aimed to investigate the 30-day mortality of patients receiving kidney replacement therapy (KRT) after infection with COVID-19, living in Australia and New Zealand between 2020 and 2022, including patients on haemodialysis (HD), peritoneal dialysis (PD) and renal transplant (KT) recipients.

METHODS

This is a retrospective cohort study using data from the Australian and New Zealand Dialysis and Transplant Registry (ANZDATA). Patients were included if they tested positive for COVID-19 infection while receiving KRT between the first reported infection in January 2020 and the end of November 2022. Multivariable logistic regression was used to assess the relationship between KRT modality and 30-day mortality following COVID-19 infection, with all potential confounders included.

RESULTS

A total of 9828 patients requiring KRT tested positive for COVID-19 within Australia and New Zealand between 2020 and 2022. The crude mortality rate by KRT modality was 3.0% for HD, 3.8% for PD and 2.4% for KT. In the adjusted model, there was a significant increase in the odds of mortality for increasing age, diabetes, peripheral vascular disease, having ever smoked and having received dialysis for ≥5 years. Relative to HD, KT recipients had increased odds of death in 2021 and 2022 but not 2020.

CONCLUSIONS

The 30-day mortality rate following COVID-19 infection in patients requiring KRT was significantly higher than the general population, with several risk factors identified associated with increased mortality rates.

B and T Cell Responses to SARS-CoV-2 Vaccination in Kidney and Liver Transplant Recipients with and without Previous COVID-19

(1) Background: Vulnerable populations including transplant recipients are jeopardised by COVID-19. Herein, we report on B and T cell responses among liver and kidney organ recipients at our centre. (2) Methods: 23 liver and 45 kidney (14 thereof combined kidney/pancreas) transplanted patients were vaccinated with two doses of BNT162b2 followed by a booster dose of mRNA-1273 in 28 non-responders 4 months thereafter. Anti-SARS-CoV-2-Ig was measured by specific ELISA and virus neutralisation assay; T cell responses were measured by a spike protein-specific IFN-γ release assay. (3) Results: Compared to controls, B and T cell responses were weak in transplant recipients, particularly in those without prior exposure to SARS-CoV-2. Within this group, only 15% after the first and 58.3% after the second vaccination achieved seroconversion. A total of 14 out of 28 vaccination non-responders achieved a seroconversion after a third dose. Vaccination side effects were more frequent in healthy controls. The use of mycophenolate was associated with reduced anti-SARS-CoV-2-Ig production. (4) Conclusions: Our data confirm that vaccination responses are insufficient after standard vaccination in liver and kidney transplant recipients and are affected to a variable degree by specific immunosuppressants, particularly mycophenolate. Monitoring vaccination success and re-vaccinating those who are unresponsive seems prudent to achieve sufficient titres. Overall, prospective large-scale, multinational, multicentre studies or high-quality meta-analyses will be needed to generate personalised vaccination strategies in order to achieve protective immunity in high-risk, hard-to-immunize populations.